rating transition和credit transition一样吗？

问题如下：

What do rating transitions measure? How stable have rating transitions been through time?

选项：

解释：

Rating transitions measure the probability that a company will move from one rating to another during a certain period. Even though ratings are through-the-cycle, downgrades tend to be higher during recessionary times.

题目问：rating transition衡量的是什么？随着时间的推移，rating transition的稳定性如何变化？

rating transition衡量的是公司在一定时间内，评级变化的可能性，即概率。

尽管评级是through-the-cycle的，但是在经济衰退的时候，downgrade降级的概率会增加。